The Rickshaw Fare
Opener: Hamza takes a rickshaw from his school to his nani's house. The rickshaw has a meter. The meter starts at Rs. 50 just for getting in. Then it adds Rs. 25 for every kilometre. Nani's house is 6 kilometres away. Hamza has Rs. 250. Will it be enough?
There is more than one way to understand this. If you have only been taught one, you have been taught less than you deserve.
There is more than one way to understand this. If you have only been taught one, you have been taught less than you deserve.
Some money problems have more than one step. You first do one calculation, then use that answer for a second one. To stay safe with money, you must finish all the steps before you decide.
Way 1, step by step: Step one, find the cost for the kilometres. 6 kilometres times Rs. 25 is Rs. 150. Step two, add the start charge. 150 plus 50 is Rs. 200. Step three, compare. 200 is less than 250. So Hamza has enough, with Rs. 50 left over.
Way 2, write a formula: Total fare equals start fee plus distance times rate. We can write it as F equals 50 plus 25 times d, where d is the kilometres. For d equal to 6, F is 50 plus 150, which is 200. Formulas let one rule answer many trips.
Way 3, work backwards: Start with Rs. 250 in the pocket. Take away Rs. 50 for the start fee. That leaves Rs. 200. Each kilometre takes away Rs. 25 from the pocket. After 1 km, Rs. 175. After 2 km, Rs. 150. After 3 km, Rs. 125. After 4 km, Rs. 100. After 5 km, Rs. 75. After 6 km, Rs. 50. Hamza arrives with Rs. 50 in his pocket.
Estimated time: 12 min